Press coining systems and methods

Abstract

A method for forming a stiffened panel includes compressing a metal blank between a first die and a second die. The second die comprises a plurality of discrete protrusions forming a grid structure in the negative spaces therebetween. In response to being compressed between the first and second dies, material of the metal blank is moved from between the plurality of discrete protrusions and the first die to the grid structure, thereby forming the stiffened panel comprising a skin and a grid of stiffening ribs. The skin of the stiffened panel has a skin thickness which is less than an initial thickness of the metal blank. The grid of stiffening ribs has a rib height which is greater than the initial thickness of the metal blank.

What is claimed is: 
     
         1 . A system for press coining a metal blank, comprising:
 a first die configured to receive the metal blank;   a second die configured to move toward the first die to compress the metal blank therebetween; and   a plurality of discrete protrusions extending from a base surface of the second die and forming a grid structure in a negative space therebetween.   
     
     
         2 . The system of  claim 1 , wherein the grid structure comprises at least one of an isogrid or an orthogrid. 
     
     
         3 . The system of  claim 1 , wherein a side cross-section of each protrusion of the plurality of discrete protrusions comprises at least one of a tapered geometry or a rounded geometry. 
     
     
         4 . The system of  claim 1 , wherein a transverse cross-section of each protrusion of the plurality of discrete protrusions comprises at least one of a quadrilateral geometry or a triangular geometry. 
     
     
         5 . The system of  claim 1 , wherein the plurality of discrete protrusions comprises:
 a first row of discrete protrusions;   a second row of discrete protrusions spaced apart from the first row of discrete protrusions by a first distance; and   a third row of discrete protrusions spaced apart from the second row of discrete protrusions by a second distance, wherein the first distance is equal to the second distance.   
     
     
         6 . The system of  claim 1 , wherein the base surface is a planar surface. 
     
     
         7 . The system of  claim 5 , wherein a ratio of the first distance and a width of a discrete protrusion of the plurality of discrete protrusions is between 1:10 and 1:30. 
     
     
         8 . The system of  claim 1 , wherein:
 the first die comprises a die recess extending into the first die from a top surface of the first die to a recess surface of the first die; and   the metal blank is configured to be received at least partially into the die recess.   
     
     
         9 . The system of  claim 8 , wherein:
 the top surface extends around a perimeter of the first die;   the die recess extends longitudinally within the first die between opposing longitudinal sides of the recess surface; and   the die recess extends laterally within the first die between opposing lateral sides of the recess surface.   
     
     
         10 . A method for forming a stiffened panel, the method comprising:
 moving a metal blank over a first die, wherein the metal blank comprises an initial thickness;   moving a second die toward the second die;   compressing the metal blank between the first die and the second die, wherein the second die comprises a plurality of discrete protrusions extending from a base surface of the second die and forming a grid structure in a negative space therebetween; and   moving material of the metal blank from between the plurality of discrete protrusions and the first die to the grid structure, thereby forming the stiffened panel comprising a skin and a grid of stiffening ribs;   wherein the skin has a skin thickness which is less than the initial thickness; and   the grid of stiffening ribs has a rib height which is greater than the initial thickness.   
     
     
         11 . The method of  claim 10 , wherein the metal blank is a planar sheet prior to being compressed between the first die and the second die. 
     
     
         12 . The method of  claim 11 , wherein the initial thickness is between 0.05 inches and inches. 
     
     
         13 . The method of  claim 10 , wherein the metal blank comprises an austenitic nickel-chromium-based alloy. 
     
     
         14 . The method of  claim 10 , further comprising, subsequent to compressing the metal blank between the first die and the second die, removing material from the metal blank to achieve at least one of a desired rib width of the grid of stiffening ribs or a desired thickness of the skin. 
     
     
         15 . The method of  claim 14 , further comprising, subsequent to removing material from the metal blank, compressing the grid of stiffening ribs to flare an end of each stiffening rib of the grid of stiffening ribs. 
     
     
         16 . The method of  claim 10 , further comprising heating the metal blank to a forging temperature prior to moving the metal blank over the first die. 
     
     
         17 . A method for forming a stiffened panel, the method comprising:
 press coining a metal blank with a first die and a second die to form a skin and a grid of stiffening ribs extending from the skin;   removing material from the metal blank to achieve at least one of a desired rib width of the grid of stiffening ribs or a desired thickness of the skin; and   compressing the grid of stiffening ribs to flare an end of each stiffening rib of the grid of stiffening ribs;   wherein, prior to the press coining, the metal blank comprises an initial thickness; and   after the press coining and prior to removing the material, the skin has a skin thickness which is less than the initial thickness and the grid of stiffening ribs has a rib height which is greater than the initial thickness.   
     
     
         18 . The method of  claim 17 , further comprising heating the metal blank to a forging temperature prior to press coining the metal blank. 
     
     
         19 . The method of  claim 17 , wherein the grid of stiffening ribs are compressed with a hydraulic press. 
     
     
         20 . The method of  claim 17 , wherein the metal blank comprises an austenitic nickel-chromium-based alloy.